/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.cocoon.forms.transformation;
import java.util.Locale;
import org.apache.avalon.excalibur.pool.Recyclable;
import org.apache.cocoon.forms.Constants;
import org.apache.cocoon.forms.formmodel.ContainerWidget;
import org.apache.cocoon.forms.formmodel.Repeater;
import org.apache.cocoon.forms.formmodel.Widget;
import org.apache.cocoon.i18n.I18nUtils;
import org.apache.cocoon.xml.AbstractXMLPipe;
import org.apache.cocoon.xml.SaxBuffer;
import org.apache.cocoon.xml.XMLUtils;
import org.apache.commons.jxpath.JXPathException;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
/**
* The basic operation of this Pipe is that it replaces wt:widget (in the
* {@link Constants#TEMPLATE_NS} namespace) tags (having an id attribute)
* by the XML representation of the corresponding widget instance.
*
* <p>These XML fragments (normally all in the
* {@link Constants#INSTANCE_NS "Cocoon Forms Instance"} namespace), can then be
* translated to a HTML presentation by an XSL. This XSL will then only have to
* style individual widget, and will not need to do the whole page layout.
*
* <p>For more information about the supported tags and their function, see the user documentation
* for the forms template transformer.</p>
*
* @version CVS $Id: WidgetReplacingPipe.java,v 1.8 2004/05/07 16:43:43 mpo Exp $
*/
public class WidgetReplacingPipe extends AbstractXMLPipe {
private static final String REPEATER_SIZE = "repeater-size";
private static final String REPEATER_WIDGET_LABEL = "repeater-widget-label";
private static final String WIDGET_LABEL = "widget-label";
private static final String WIDGET = "widget";
private static final String LOCATION = "location";
private static final String REPEATER_WIDGET = "repeater-widget";
private static final String CONTINUATION_ID = "continuation-id";
private static final String FORM_TEMPLATE_EL = "form-template";
private static final String STYLING_EL = "styling";
protected Widget contextWidget;
/**
* Indicates whether we're currently in a widget element.
*/
protected boolean inWidgetElement;
/**
* Buffer used to temporarily record SAX events.
*/
protected SaxBuffer saxBuffer;
/**
* Counts the element nesting.
*/
protected int elementNestingCounter;
/**
* Contains the value of the {@link #elementNestingCounter} on the moment the transformer
* encountered a wi:widget element. Used to detect the corresponding endElement call
* for the wi:widget element.
*/
protected int widgetElementNesting;
/**
* If {@link #inWidgetElement} = true, then this contains the widget currenlty being handled.
*/
protected Widget widget;
/**
* Boolean indicating wether the current widget requires special repeater-treatement.
*/
protected boolean repeaterWidget;
protected WidgetReplacingPipe.InsertStylingContentHandler stylingHandler = new WidgetReplacingPipe.InsertStylingContentHandler();
protected FormsPipelineConfig pipeContext;
/**
* Have we encountered a <wi:style> element in a widget ?
*/
protected boolean gotStylingElement;
/**
* Namespace prefix used for the namespace <code>Constants.FT_NS</code>.
*/
protected String namespacePrefix;
public void init(Widget newContextWidget, FormsPipelineConfig newPipeContext) {
contextWidget = newContextWidget;
inWidgetElement = false;
elementNestingCounter = 0;
pipeContext = newPipeContext;
}
public void startElement(String namespaceURI, String localName, String qName, Attributes attributes)
throws SAXException {
elementNestingCounter++;
if (inWidgetElement) {
if (elementNestingCounter == widgetElementNesting + 1 &&
Constants.INSTANCE_NS.equals(namespaceURI) && STYLING_EL.equals(localName)) {
gotStylingElement = true;
}
saxBuffer.startElement(namespaceURI, localName, qName, attributes);
} else if (Constants.TEMPLATE_NS.equals(namespaceURI)) {
if (localName.equals(WIDGET) || localName.equals(REPEATER_WIDGET)) {
checkContextWidgetAvailable(qName);
inWidgetElement = true;
widgetElementNesting = elementNestingCounter;
gotStylingElement = false;
saxBuffer = new SaxBuffer();
// retrieve widget here, but its XML will only be streamed in the endElement call
widget = getWidget(attributes);
repeaterWidget = localName.equals(REPEATER_WIDGET);
if (repeaterWidget && !(widget instanceof Repeater)) {
throw new SAXException("FormsTemplateTransformer: the element \"repeater-widget\" can only be used for repeater widgets.");
}
} else if (localName.equals(WIDGET_LABEL)) {
checkContextWidgetAvailable(qName);
Widget widget = getWidget(attributes);
widget.generateLabel(contentHandler);
} else if (localName.equals(REPEATER_WIDGET_LABEL)) {
checkContextWidgetAvailable(qName);
Widget widget = getWidget(attributes);
if (!(widget instanceof Repeater)) {
throw new SAXException("FormsTemplateTransformer: the element \"repeater-widget-label\" can only be used for repeater widgets.");
}
String widgetId = attributes.getValue("widget-id");
if (widgetId == null || widgetId.equals("")) {
throw new SAXException("FormsTemplateTransformer: the element \"repeater-widget-label\" requires a \"widget-id\" attribute.");
}
((Repeater)widget).generateWidgetLabel(widgetId, contentHandler);
} else if (localName.equals(REPEATER_SIZE)) {
checkContextWidgetAvailable(qName);
Widget widget = getWidget(attributes);
if (!(widget instanceof Repeater))
throw new SAXException("FormsTemplateTransformer: the element \"repeater-size\" can only be used for repeater widgets.");
contentHandler.startPrefixMapping(Constants.INSTANCE_PREFIX, Constants.INSTANCE_NS);
((Repeater)widget).generateSize(contentHandler);
contentHandler.endPrefixMapping(Constants.INSTANCE_PREFIX);
} else if (localName.equals(FORM_TEMPLATE_EL)) {
if (contextWidget != null) {
throw new SAXException("Detected nested ft:form-template elements, this is not allowed.");
}
contentHandler.startPrefixMapping(Constants.INSTANCE_PREFIX, Constants.INSTANCE_NS);
// ====> Retrieve the form
// first look for the form using the location attribute, if any
String formJXPath = attributes.getValue(LOCATION);
if (formJXPath != null) {
// remove the location attribute
AttributesImpl attrsCopy = new AttributesImpl(attributes);
attrsCopy.removeAttribute(attributes.getIndex(LOCATION));
attributes = attrsCopy;
}
contextWidget = pipeContext.findForm(formJXPath);
// ====> Determine the Locale
//TODO pull this locale stuff also up in the Config object?
String localeAttr = attributes.getValue("locale");
if (localeAttr != null) { // first use value of locale attribute if any
localeAttr = pipeContext.translateText(localeAttr);
pipeContext.setLocale(I18nUtils.parseLocale(localeAttr));
} else if (pipeContext.getLocaleParameter() != null) { // then use locale specified as transformer parameter, if any
pipeContext.setLocale(pipeContext.getLocaleParameter());
} else { // use locale specified in bizdata supplied for form
Object locale = null;
try {
locale = pipeContext.evaluateExpression("/locale");
} catch (JXPathException e) {}
if (locale != null) {
pipeContext.setLocale((Locale)locale);
}
else {
// final solution: use locale defined in the server machine
pipeContext.setLocale(Locale.getDefault());
}
}
String[] namesToTranslate = {"action"};
Attributes transAtts = translateAttributes(attributes, namesToTranslate);
contentHandler.startElement(Constants.INSTANCE_NS , FORM_TEMPLATE_EL, Constants.INSTANCE_PREFIX_COLON + FORM_TEMPLATE_EL, transAtts);
} else if (localName.equals(CONTINUATION_ID)){
// Insert the continuation id
// FIXME(SW) we could avoid costly JXPath evaluation if we had the objectmodel here.
Object idObj = pipeContext.evaluateExpression("$continuation/id");
if (idObj == null) {
throw new SAXException("No continuation found");
}
String id = idObj.toString();
contentHandler.startPrefixMapping(Constants.INSTANCE_PREFIX, Constants.INSTANCE_NS);
contentHandler.startElement(Constants.INSTANCE_NS, CONTINUATION_ID, Constants.INSTANCE_PREFIX_COLON + CONTINUATION_ID, attributes);
contentHandler.characters(id.toCharArray(), 0, id.length());
contentHandler.endElement(Constants.INSTANCE_NS, CONTINUATION_ID, Constants.INSTANCE_PREFIX_COLON + CONTINUATION_ID);
contentHandler.endPrefixMapping(Constants.INSTANCE_PREFIX);
} else {
throw new SAXException("FormsTemplateTransformer: Unsupported element: " + localName);
}
} else {
super.startElement(namespaceURI, localName, qName, attributes);
}
}
private void checkContextWidgetAvailable(String widgetElementName) throws SAXException {
if (contextWidget == null)
throw new SAXException(widgetElementName + " cannot be used outside a wt:form-template element");
}
private Attributes translateAttributes(Attributes attributes, String[] names) {
AttributesImpl newAtts = new AttributesImpl(attributes);
if (names!= null) {
for (int i = 0; i < names.length; i++) {
String name = names[i];
int position = newAtts.getIndex(name);
String newValue = pipeContext.translateText(newAtts.getValue(position));
newAtts.setValue(position, newValue);
}
}
return newAtts;
}
protected Widget getWidget(Attributes attributes) throws SAXException {
String widgetId = attributes.getValue("id");
if (widgetId == null || widgetId.equals("")) {
throw new SAXException("FormsTemplateTransformer: missing id attribute on a Cocoon Forms element.");
}
Widget widget = ((ContainerWidget)contextWidget).getChild(widgetId);
if (widget == null) {
throw new SAXException("FormsTemplateTransformer: widget with id \"" + widgetId + "\" does not exist in the container " + contextWidget.getRequestParameterName());
}
return widget;
}
public void endElement(String namespaceURI, String localName, String qName)
throws SAXException {
if (inWidgetElement) {
if (elementNestingCounter == widgetElementNesting && Constants.TEMPLATE_NS.equals(namespaceURI)
&& (localName.equals(WIDGET) || localName.equals(REPEATER_WIDGET))) {
if (repeaterWidget) {
Repeater repeater = (Repeater)widget;
WidgetReplacingPipe rowPipe = new WidgetReplacingPipe();
int rowCount = repeater.getSize();
for (int i = 0; i < rowCount; i++) {
Repeater.RepeaterRow row = repeater.getRow(i);
rowPipe.init(row, pipeContext);
rowPipe.setContentHandler(contentHandler);
rowPipe.setLexicalHandler(lexicalHandler);
saxBuffer.toSAX(rowPipe);
rowPipe.recycle();
}
} else {
stylingHandler.recycle();
stylingHandler.setSaxFragment(saxBuffer);
stylingHandler.setContentHandler(contentHandler);
stylingHandler.setLexicalHandler(lexicalHandler);
contentHandler.startPrefixMapping(Constants.INSTANCE_PREFIX, Constants.INSTANCE_NS);
widget.generateSaxFragment(stylingHandler, pipeContext.getLocale());
contentHandler.endPrefixMapping(Constants.INSTANCE_PREFIX);
}
inWidgetElement = false;
widget = null;
} else {
saxBuffer.endElement(namespaceURI, localName, qName);
}
} else if (Constants.TEMPLATE_NS.equals(namespaceURI)) {
if (localName.equals(WIDGET_LABEL) || localName.equals(REPEATER_WIDGET_LABEL)
|| localName.equals(REPEATER_SIZE) || localName.equals(CONTINUATION_ID)) {
// Do nothing
} else if (localName.equals(FORM_TEMPLATE_EL)) {
contextWidget = null;
contentHandler.endElement(Constants.INSTANCE_NS, FORM_TEMPLATE_EL,
Constants.INSTANCE_PREFIX_COLON + FORM_TEMPLATE_EL);
contentHandler.endPrefixMapping(Constants.INSTANCE_PREFIX);
} else {
super.endElement(namespaceURI, localName, qName);
}
} else {
super.endElement(namespaceURI, localName, qName);
}
elementNestingCounter--;
}
public void startPrefixMapping(String prefix, String uri)
throws SAXException {
if (inWidgetElement) {
saxBuffer.startPrefixMapping(prefix, uri);
} else {
super.startPrefixMapping(prefix, uri);
}
}
public void endPrefixMapping(String prefix)
throws SAXException {
if (inWidgetElement) {
saxBuffer.endPrefixMapping(prefix);
} else {
super.endPrefixMapping(prefix);
}
}
public void characters(char c[], int start, int len)
throws SAXException {
if (inWidgetElement) {
saxBuffer.characters(c, start, len);
} else {
super.characters(c, start, len);
}
}
public void ignorableWhitespace(char c[], int start, int len)
throws SAXException {
if (inWidgetElement) {
saxBuffer.ignorableWhitespace(c, start, len);
} else {
super.ignorableWhitespace(c, start, len);
}
}
public void processingInstruction(String target, String data)
throws SAXException {
if (inWidgetElement) {
saxBuffer.processingInstruction(target, data);
} else {
super.processingInstruction(target, data);
}
}
public void skippedEntity(String name)
throws SAXException {
if (inWidgetElement) {
saxBuffer.skippedEntity(name);
} else {
super.skippedEntity(name);
}
}
public void startEntity(String name)
throws SAXException {
if (inWidgetElement)
saxBuffer.startEntity(name);
else
super.startEntity(name);
}
public void endEntity(String name)
throws SAXException {
if (inWidgetElement) {
saxBuffer.endEntity(name);
} else {
super.endEntity(name);
}
}
public void startCDATA()
throws SAXException {
if (inWidgetElement) {
saxBuffer.startCDATA();
} else {
super.startCDATA();
}
}
public void endCDATA()
throws SAXException {
if (inWidgetElement) {
saxBuffer.endCDATA();
} else {
super.endCDATA();
}
}
public void comment(char ch[], int start, int len)
throws SAXException {
if (inWidgetElement) {
saxBuffer.comment(ch, start, len);
} else {
super.comment(ch, start, len);
}
}
public void recycle() {
super.recycle();
this.contextWidget = null;
this.widget = null;
this.namespacePrefix = null;
}
/**
* This ContentHandler helps in inserting SAX events before the closing tag of the root
* element.
*/
public class InsertStylingContentHandler extends AbstractXMLPipe implements Recyclable {
private int elementNesting;
private SaxBuffer saxBuffer;
public void setSaxFragment(SaxBuffer saxFragment) {
saxBuffer = saxFragment;
}
public void recycle() {
super.recycle();
elementNesting = 0;
saxBuffer = null;
}
public void startElement(String uri, String loc, String raw, Attributes a)
throws SAXException {
elementNesting++;
super.startElement(uri, loc, raw, a);
}
public void endElement(String uri, String loc, String raw)
throws SAXException {
elementNesting--;
if (elementNesting == 0 && saxBuffer != null) {
if (gotStylingElement) {
// Just deserialize
saxBuffer.toSAX(contentHandler);
} else {
// Insert an enclosing <wi:styling>
contentHandler.startElement(Constants.INSTANCE_NS, STYLING_EL, Constants.INSTANCE_PREFIX_COLON + STYLING_EL, XMLUtils.EMPTY_ATTRIBUTES);
saxBuffer.toSAX(contentHandler);
contentHandler.endElement(Constants.INSTANCE_NS, STYLING_EL, Constants.INSTANCE_PREFIX_COLON + STYLING_EL);
}
}
super.endElement(uri, loc, raw);
}
}
}